Final answer:
A biopsy is performed to determine if tissue cells are cancerous by microscopic examination, immunohistochemistry, and medical imaging, which identifies cell abnormalities and informs treatment strategies.
Step-by-step explanation:
To determine whether cells from a tissue sample are cancerous, oncologists perform a biopsy. The procedure involves surgically removing a tissue specimen for microscopic examination by a pathologist. Once the sample is obtained, a variety of tests can be conducted, including looking at cell size and shape, staining for specific molecules, and immunohistochemistry to detect the presence of cell-surface antigens with labeled antibodies. These methods provide information about the type of cancer, such as carcinoma or sarcoma, and can help determine the cancer's stage and appropriate treatment options.
In addition to microscopic examination, medical imaging such as CT scans or MRIs can be used to assess if and how far the cancer has spread. For instance, the diagnosis of cervical cancer often begins with a Pap smear, followed by a biopsy if abnormal cells are detected. In the case of lymphoma, identifying specific cell-surface proteins helps pathologists ascertain the precise type of lymphoma, which is crucial for selecting the best treatment.